Incandescent electric lamp



UNITED STATES PATIJINT OFFICE.

ALEXANDER BERNSTEIN, OF BOSTON, MASSACHUSETTS.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 280,340, dated July 3,1883.

' Application filed February 5. 1883, (No model.) I

To aZZ whom it may concern.-

Be it known that I, A EX. BERNSTEIN, of Boston, in the county of Suffolkand State of Massachusetts,haveinvented certain Improvements inIncandescent Electric Lamps, of

which the following is a specification.

My invention relates to that class of electric I lamps in which thelight is produced by the incandescence of a light-giving conductorinclosed in a glass globe; and it more particularly concerns theconstruction of devices by which the said conductors are united to thewires leading into the bulb or globe of the lamp.

1 In Letters Patent issued to me, dated J anuary 30, 1883, I have shownand described an electric lamp in which a hollow or tubular carbon isused as the light-giving conductor. I have therein stated that the saidtubular carbon is supported at each end in carbon sockets, to which theconducting-wires leading into and out of the lamp are attached.Experience has demonstrated that a junction, perfect both electricallyand mechanically, between the carbon socket and the light-giving carbonand between the socket and the leading-in wires or 1 conductors is amatter of great importance, and is, in fact, essential to the properworking of the lamp. I have accordingly devised an improved method bywhich the junction may be made. It is self-evident that a mere fittingof the hollow carbon into the socket would not answer, as in that casearcing anddisintegration of the carbon would soon take place. A 3 5perfect contact is equally requisite between the socket and theconducting-wires to prevent undue heating and melting of the wires,which a defective contact would produce.

In Figure l a section of the carbon socket A is shown, and the saidsocket, exteriorly, may be of any desired shape or configuration. Acylindrical hole, a,is bored in the upper part of the socket, and thishole is made slightly larger than the outside diameter of the light- 5giving carbon. A smaller cylindrical hole, I), is then bored a shortdistance into the other end or bottom part 'of the socket, this holebeing just large enough to let the necessary conducting-wire passthrough. The space 0 between the two holes a and b is bored outtapering, as indicated. Fig. 5 is a sectional view on line :1. :r,Fig. 1. The socket being now prepared, the conductingwire is firstjoined thereto. This wire B is shown in Fig. 2, its upper end being inthe form of an inverted cone, (1, which fits the taper hole a in thesocket. Before inserting the conducting-wire in place, a mixture ofpowdered or pulverized carbon with sirup, gum, or similar substancewhich will carbonize on being heated is dropped into the socket in orderto fill any space which may be left between the socket and that part ofthe leading-in wire which rests therein. The wire B and socket A, whenunited, have the form shown in Fig. 3, that part of the figurerepresenting the socket be. ing still shown in section. The next operation consists in putting one of the sockets thus prepared on each end ofthe hollow carbon cylinder. I employ at this stage of the manu 7ofacture the same mixture of powdered carbon and gum, sirup, or similarsubstance which I have hereinbefore referred to, and in this case,

as in the former operation, I may, if I prefer, dispense with the use ofpowdered carbon, by merely using sirups, or any carbonaceous cement oflike nature which carbonizes when heated. After both ends of the hollowcarbon are provided. as described, with sockets, the whole presents theappearance shown in Fig. 4, in which A A are sockets; B B, theleadingwires cemented therein, and O the light-giving part inserted inthe holes a. The various component parts, being thus put together, arenow placed in a suitable furnace, and heated until the gum, sirup, orother carbonaceous cement which has been employed at the severaljunctions is fully carbonized, after which the elec trical andmechanical connection between the different parts is perfect, the wholeforming a continuous and homogeneous conductor; from one end to theother. The pieces, when put together, as in Fig. 4, form a separatearticle of manufacture, which may be used in incandescent lamps invarious ways, as I shall show in future applications. Instead of using aready-'made socket, I may, if I prefer, form such a one around thetubular carbon by ap plying thereto successive layers of powdered carbonwith gum or sirup, and carbonizing I00 one layer after another, theconducting-wires being introduced between the several layers; but thisis an inferior method, generally speaking, and will only be adopted inspecial cases.

Having now fully described my said invention and the manner'in which thesame is to be carried into effect, I would observe, in con clusion, thatalthough I have described a method of connecting tubular light-givingcarbons with sockets and connecting-wires, I make no claim hereinthereto, but reserve the same for a separate application.

I claim The combination, substantially as hereinbefore described, in anincandescent electric lamp, of a light-giving hollow carbon cylinder,and conical headed conducting Wires therefor, with supporting-sockets ofcarbon placed at each end of the hollow cylindrical carbon, and betweenthe same and the conduct Witnesses:

GEO. WILLIS PIERCE, J. H. GHEEVER.

